Sen. Rand Paul (R-Ky.) announced Friday he would definitely be running in 2016 -- for the U.S. Senate, that is.

"For now, [what] we know for sure is we're going to run for the U.S. Senate," Paul said, according to a report from CNN. "The other decision can come later."

That "other decision" involves a potential presidential run, which Paul has already been gearing up for with visits to big primary states like Iowa and New Hampshire. During those appearances, Paul pushed for changes within the Republican party.

"I do know the GOP needs to grow and I want to be part of growing the GOP," Paul said during a stop in Cedar Rapids, Iowa.

Paul's not the only Republican who may be vying for a shot at the Republican presidential candidacy in 2016. Reuters reported earlier:

With no clear presidential front-runner in their party, Republicans are in shopping mode.

They are looking for signs of a candidate who could unite the party's religious right, its more moderate establishment and its libertarian, anti-tax Tea Partiers in a way that Mitt Romney, the 2012 presidential nominee, could not do.

And they are looking for someone who could appeal to - or at least not offend - Hispanics, non-white women and other parts of the electorate that went big for Obama and Democrats last year.

That's why, just four months into Obama's second term, Paul is part of a stampede of Republican would-be contenders who are criss-crossing the country meeting voters, recruiting potential donors and currying favor with local politicians who could help determine their fate in a run for the White House.

On Feb. 21, 2013, <a href="http://hosted-p0.vresp.com/1174985/8b2d5dc5f6/ARCHIVE">The American Conservative Union</a> released its 2012 conservative ratings guide. Which members of Congress had a perfect score?